Introduction 1 6 1 2 2 7 4 8 12 12 13 5 10 8 14 15 14 9 3 4 spatial temporal 2+ Materials and methods Confocal Raman microspectroscopy 1  X Y  Z −1 −1 Fig. 1 Schematic of experimental setup  Microfluidic device fabrication 16 18 2 2 Fig. 2 a b c  2 Cell culture and assay reagents Cricetulus griseus  L  L 2 6 −1  D 2 2 2 −1 Gold colloid with a particle size of 50 nm (EM.GC50), suspended in water, was supplied by BBinternational Ltd, UK. The gold nanoparticles were introduced into cells by a passive uptake method where the cells were incubated with gold colloid solution at desired concentration (20% colloid solution, v/v) and room temperature for 50 mins. Prior to loading into the microfluidic chip, the cells were washed with wash solution to remove the culture media and gold nanoparticles outside cells. The cells were re-suspended in the wash solution for measurements. Results and discussion SERS effects 2 19 20 14 3 −1 3 21 Fig. 3 upper  spectrum lower  spectrum  Characterization of single living cells by 3D mapping −1 11 22 23 4 2  X  Y 4 −1 11 23 Fig. 4 a  X Y b  1 8 9 12 23 27  X Y 4 −1 −1 −1 −1 −1 1 −1 Table 1 Band assignment for Raman spectra of CHO cells −1 Assignments DNA/RNA Proteins Lipids 830 12 23 24 12 23 24  895 12 23 24   940  ν 9 12 23  1,004  9 12 23  1,065 ν 12 23 ν 25  1,126  ν 9 12 23 ν 25 1,144 12 23   1,157 20 26   1,176 9 12 23 24 12 23  1,230 12 23 24   1,266  25 δ 2 25 1,295   δ 2 25 1,320 24   1,342 12 23 24   1,376 9 12 23 24   1,448  δ 9 12 23 δ 9 12 23 1,482 12 23 24   1,566  25  1,578 12 23 24   1,603 24   1,643  27  BkB Tyr A  T G C  ν δ  Z 5 5 −1  Z 23 −1  Z 8 12 23 Fig. 5  Z  15 In situ monitoring of cellular chemical dynamics 3 28 −1 −1 6 6 −1 27 6 2+ 3 29 Fig. 6 a  first spectrum b c −1  Conclusions  X Y spatial temporal 2+